CHANGES IN ACTIVITIES OF CREATINE KINASE, ARGININE KINASE AND THEIR MULTIENZYME FORMS DURING EMBRYONIC AND LARVAL DEVELOPMENT OF SEA URCHINS

The presence and the changes of CPK and APK have been studied during larval development through metamorphosing of Hemicentrotus pulcherrimus, Anthocidaris crassispina and Pseudo‐centrotus depressus . While no CPK activity was found in the unfertilized eggs and the embryos of early developmental stages, APK was quite active throughout these stages. At the late 8‐armed pluteus stage just prior to metamorphosis, CPK first became active. Electrophoretically this CPK was identical with one of three CPK forms of sperm, tube feet and esophagus but not with two CPK forms of lantern muscle. APK in the unfertilized eggs and early embryos was electrophoretically separated into two distinct molecular forms, one of which disappeared during the late larval stages. The persisting form of larval APK was identical with a single APK form present in the adult muscular tissues.